op mijn website www.fotorr.tk heb ik knoppen met geplaatst in layers, in IE geen enkel probleem, maar in firefox verspringt er één en ik vind niet waarom, hier de code
<div id="Layer3" style="position:absolute; left:565px; top:110px; width:100px; height:25px; z-index:3; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"><strong><font color="#FFFFFF" face="Arial, Helvetica, sans-serif"><a href="index.htm">Home</a></font></strong></div>
</div>
<div id="Layer4" style="position:absolute; left:662px; top:110px; width:100px; height:25px; z-index:4; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"><strong><font color="#FFFFFF" face="Arial, Helvetica, sans-serif"><a href="landen.htm">Landen</a></font></strong></div>
</div>
<div id="Layer5" style="position:absolute; left:762px; top:110px; width:100px; height:25px; z-index:5; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"><font color="#FFFFFF" face="Arial, Helvetica, sans-serif"><strong><a href="fotografie_vieuwer/index_fotogr.html">Fotografie</a></strong></font></div>
</div>
<div id="Layer6" style="position:absolute; left:861px; top:110px; width:100px; height:25px; z-index:6; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"
<div id="Layer3" style="position:absolute; left:565px; top:110px; width:100px; height:25px; z-index:3; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"><strong><font color="#FFFFFF" face="Arial, Helvetica, sans-serif"><a href="index.htm">Home</a></font></strong></div>
</div>
<div id="Layer4" style="position:absolute; left:662px; top:110px; width:100px; height:25px; z-index:4; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"><strong><font color="#FFFFFF" face="Arial, Helvetica, sans-serif"><a href="landen.htm">Landen</a></font></strong></div>
</div>
<div id="Layer5" style="position:absolute; left:762px; top:110px; width:100px; height:25px; z-index:5; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"><font color="#FFFFFF" face="Arial, Helvetica, sans-serif"><strong><a href="fotografie_vieuwer/index_fotogr.html">Fotografie</a></strong></font></div>
</div>
<div id="Layer6" style="position:absolute; left:861px; top:110px; width:100px; height:25px; z-index:6; background-image: url(achtergrond2.jpg); layer-background-image: url(achtergrond2.jpg); border: 1px none #000000;">
<div align="center"